On "that other site" I never had the trouble of being "kicked out" if I left in the middle of a reply and then came back to it ten minutes later.
It happened twice today. First time caught me unawares, next time I was savvy enough to hit ctrl c prior to hitting submit.
I logged on..started composing..got interrupted, came back to reply, finished typing, hit 'submit', and the reply was lost as I was not "logged on".
perhaps a glitch?